Dark Matter maps the invisible dimension of theater whose effects are felt everywhere in performance. Examining phenomena such as hallucination, offstage character, offstage action, sexuality, masking, technology, and trauma, Andrew Sofer engagingly illuminates the invisible in different periods of postclassical western theater and drama. He reveals how the invisible continually structures and focuses an audience's theatrical experience, whether it's black magic in Doctor Faustus, offstage sex in A Midsummer Night's Dream, masked women in The Rover, self-consuming bodies in Suddenly Last Summer, or surveillance technology in The Archbishop's Ceiling. Each discussion pinpoints new and striking facets of drama and performance that escape sight. Taken together, Sofer's lively case studies illuminate how dark matter is woven into the very fabric of theatrical representation. Written in an accessible style and grounded in theater studies but interdisciplinary by design, Dark Matter will appeal to theater and performance scholars, literary critics, students, and theater practitioners, particularly playwrights and directors.